1. Field of the Invention
The present invention relates to a braille recognition system.
2. Description of the Prior Art
Currently in six-point braille generally employed, six points comprising three columns of points and two rows of points are taken as one unit, and characters are constructed by a combination of the projected points. This unit is referred to as a "masu".
In each masu, the projected point in the uppermost stage of the left column, the projected point in the intermediate stage of the left column, the projected point in the lowermost stage of the left column, the projected point in the uppermost stage of the right column, the projected point in the intermediate stage of the right column, and the projected point in the lowermost stage of the right column are respectively referred to as point 1, point 2, point 3, point 4, point 5, and point 6.
The spacing W1 between the projected points adjacent to each other in the lateral direction in the same masu is generally set to 2.0 to 2.1 mm. Further, the spacing W2 between the projected points adjacent to each other in the lateral direction between adjacent masus is generally set to 3.0 to 3.1 mm.
The braille is horizontal writing, which is read from the left to the right. In the six-point braille, 63 types of different combinations are possible. However, it is impossible to represent all of kana characters, numeric characters and alphabetic characters by 63 types of combinations. When a numeric character or an alphabetic character is represented, therefore, a code referred to as a pre-code for identifying a character system is assigned ahead of the numeric character or the alphabetic character.
A character on printed matter is referred to as a character in India ink, in contrast with braille. As a code corresponding to the braille, NABCC (North American Braille Computer Code) is generally used.
The braille is represented by projected points, unlike a general character. The braille is represented by the presence or absence of the six projected points. Therefore, the applicant of the present invention has developed a braille recognition system using a recognition method different from a general character recognition method, to file an application (Japanese Patent Application No. 1995/152853). Thereafter, the applicant has continued the research, to develop a method of automatically recognizing braille on the surface and the reverse surface of a document in braille having braille printed on both its surfaces from a picked-up image on one of the surfaces of the document in braille.